NAME¶

dblink_fetch - returns rows from an open cursor in a remote database

SYNOPSIS¶

dblink_fetch(text cursorname, int howmany [, bool fail_on_error]) returns setof record
dblink_fetch(text connname, text cursorname, int howmany [, bool fail_on_error]) returns setof record

DESCRIPTION¶

dblink_fetch fetches rows from a cursor previously established by dblink_open.

ARGUMENTS¶

connname

cursorname

howmany

fail_on_error

RETURN VALUE¶

The function returns the row(s) fetched from the cursor. To use this function, you will need to specify the expected set of columns, as previously discussed for dblink.

NOTES¶

On a mismatch between the number of return columns specified in the FROM clause, and the actual number of columns returned by the remote cursor, an error will be thrown. In this event, the remote cursor is still advanced by as many rows as it would have been if the error had not occurred. The same is true for any other error occurring in the local query after the remote FETCH has been done.

EXAMPLES¶

SELECT dblink_connect('dbname=postgres options=-csearch_path=');


 dblink_connect
----------------


 OK
(1 row)
SELECT dblink_open('foo', 'select proname, prosrc from pg_proc where proname like ''bytea%''');


 dblink_open
-------------


 OK
(1 row)
SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);


 funcname |  source
----------+----------


 byteacat | byteacat


 byteacmp | byteacmp


 byteaeq  | byteaeq


 byteage  | byteage


 byteagt  | byteagt
(5 rows)
SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);


 funcname  |  source
-----------+-----------


 byteain   | byteain


 byteale   | byteale


 bytealike | bytealike


 bytealt   | bytealt


 byteane   | byteane
(5 rows)
SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);


  funcname  |   source
------------+------------


 byteanlike | byteanlike


 byteaout   | byteaout
(2 rows)
SELECT * FROM dblink_fetch('foo', 5) AS (funcname name, source text);


 funcname | source
----------+--------
(0 rows)